Problem: Simplify the following expression: $\sqrt{325} - \sqrt{117}$
Solution: First, try to factor any perfect squares out of the radicals. $= \sqrt{325} - \sqrt{117}$ $= \sqrt{25 \cdot 13} - \sqrt{9 \cdot 13}$ Separate the radicals and simplify. $= \sqrt{25} \cdot \sqrt{13} - \sqrt{9} \cdot \sqrt{13}$ $= 5\sqrt{13} - 3\sqrt{13}$ Finally, simplify by combining the terms. $= ( 5 - 3 )\sqrt{13} = 2\sqrt{13}$